Microbes may often be present on many common objects and surfaces in everyday life. Microbes can include, for example, bacteria, fungi, spores, viruses, prions, microorganisms such as, e.g., Mycobacterium tuberculosis, listeria monocytogenas, escherichia coli, pseudomonas aeruginosa, salmonella typhimurium, salmonella enteritidis, delegionella bacteria, Yersinia pestis, staphylococcus aereus, bacillus subtilis, enterobacter aerogenes, streptococcus faecalis, legionella pneumophila, viibrio parahaemolyticus, bacillus cereus, and other gram positive and gram negative microorganisms. Several such microbes/microorganisms, individually or in combination, can cause illness or other health problems, for example, when they come into contact with humans and/or animals, or when they are ingested along with food which has contacted them.
Surfaces can be treated using various techniques to reduce or eliminate the presence of microorganisms. Such cleaning, disinfecting, or “sterilization” techniques can be performed, e.g., using chemicals (for example, by application of disinfectant sprays or solutions), heat, steam, pressure, ultraviolet light or other radiation, etc., or combinations of such techniques. Disinfection of surfaces to reduce or eliminate a presence of microorganisms can be non-permanent, costly, inconvenient, ineffective, and/or time-consuming.
There is an increasing need for “antimicrobial” materials and surfaces which may be capable of killing such microbes/microorganisms and/or inhibiting growth or spreading thereof.
Certain industries, such as the health care and medical industry, may have a particular need for micro-organism-resistant surfaces. For example, hospitals and other medical facilities may have a particular need for sterile and uncontaminated surfaces, both in surgical areas as well as in convalescence facilities, where patient exposure may be significant and resistance to such microbes may be lowered. Much time and effort can be spent, for example, on sterilizing medical instruments, testing devices, etc. Often, such devices can be provided with disposable components or covers (e.g., disposable thermometer probes) to avoid cross-contamination between patients. Disposable needles are also commonly used. Such disposable materials involve increased costs and increased waste, as well as potential safety issues associated with their disposal.
The food-preparation and delivery industry is another area in which presence of microbes (e.g., bacteria) can be problematic. Food preparation facilities, if contaminated with microbes, can lead to contamination of food which may cause health problems when ingested. For example, restaurants, food manufacturing plants, and even home kitchens can contain preparation surfaces, utensils, and equipment which may contaminate food that comes into contact with them. There may be, for example, a particular need for reducing a presence and spreading of microbes in meat packaging plants.
Public and private facilities such as, e.g., restrooms, may also contain surfaces which can harbor and spread microbes, leading to potential health problems. To address this issue, products such as antimicrobial soaps and air dryers for hands may be offered, as well as disposable paper towels. Nevertheless, microbes may still be harbored on such objects as faucet and toilet handles, door knobs, keys, dispenser levers, etc.
In the transportation industry, including land, sea, air, and space vehicles, there may also be particular surfaces which can harbor and spread microbes, leading to potential health problems. For example, rental cars may benefit from durable antimicrobial surfaces (both interior and exterior). In particular, isolated environments such as, e.g., airplanes and submarines can also be safer if provided with antimicrobial surfaces.
Other common objects may benefit from antimicrobial surfaces, which can inhibit or prevent spread of microorganisms between people and/or animals that come into contact with such objects. For example, musical instruments, such as harmonicas, flutes, clarinets, etc., computer peripherals, communications equipment such as, e.g., telephones, pet accessories such as leashes and carriers, and/or other common household objects could benefit from antimicrobial surfaces.
Microbes can be present on a wide variety of materials and surfaces. Porous surfaces and surfaces which may often be damp or wet can provide moisture, nutrients, and/or other conditions which may promote growth and spreading of microbes. Common porous surfaces can include, e.g., kitchen sponges, cutting boards, and the like. Even metallic materials (e.g., stainless steel) can have small crevices and ridges which can foster growth of microbes. Thus, items such as medical instruments and kitchen utensils may present health problems if not properly and frequently cleaned, disinfected, and/or sterilized. Objects provided in hospitals, sterile laboratories, and other such “clean” facilities, including medical instruments, autoclaves, sterilizers, etc., may particularly benefit if provided with durable antimicrobial surfaces.
Certain materials and procedures have been developed to reduce or prevent a presence of microbes on certain surfaces. For example, compounds which may exhibit antimicrobial activity such as, e.g., certain salts or nanoparticles of silver, can be applied to certain substrates. Such antimicrobial coatings may be capable of killing or inhibiting growth of certain microbes. Application of such antimicrobial coatings may often be performed using solution chemistry or by combining antimicrobial compounds with polymers, resins, or other materials to coat a surface, where such materials may often be at least partially organic. However, such coatings may have limited lifetimes for killing or inhibiting growth of microbes. More importantly, such coatings may often not adhere well to the substrate, or they may only adhere to certain types of substrates. Further, such antimicrobial coatings may wear off to some degree when exposed to various environments or conditions (e.g., heat, abrasion, chemicals). Such wear, which can occur rapidly, may reduce or eliminate the ability of these coatings to kill or inhibit growth of microbes over time.
Thus, there may be a need for improved antimicrobial surfaces, coatings, and materials which are durable and effective in killing or inhibiting growth of microbes such as bacteria and other microorganisms. Further, there may be a need to provide such materials and coatings which are easy and relatively inexpensive to produce, and which may be applied to a broad variety of substrates. In addition, there may be a need for such antimicrobial coatings which can be applied to objects that are already in use or that are in need of repair.